فصلنامه بهداشت در عرصه
سال دوم شماره 1 (پیاپی 5، بهار 1393)

In view of water crisis، effective prevention of water resources contamination is increasingly important. The presence of heavy metals in drinking water at concentration greater than acceptable limits may result in various adverse health effects. The present study was therefore conducted to evaluate the concentrations of arsenic (As)، cadmium (Cd)، lead (Pb) and copper (Cu) in drinking water supplies of villages located in southeastern region of Rafsanjan plain and in Rafsanjan fault zone as well. Samples were taken from 62 rural drinking water supply resources (springs، wells، and canals). The concentrations of As، Cd، Pb and Cu was thence measured by atomic absorption following sample preparation. Statistical analysis was performed using SPSS software (version 16). Copper concentrations were less than both WHO guidelines and the official Iranian government standard No. 1053 for the chemical quality of water in all samples. The amounts of As، Pb and Cd، however، fail to meet basic standards of water quality in 31. 7%، 25% and 58. 1% of samples، respectively. The current study also found that about 10. 4% of people in this study area were exposed to arsenic. Furthermore، the results of this study revealed that respectively 66. 6% and 46. 7% of the study area residents had been exposed to high levels of lead and cadmium. The heavy metals contamination of drinking water resources in Rafsanjan plain is linked to both naturally presence of sulfide veins in this area and manmade pollution due to the presence of main road as well as pesticides releases from agricultural activities. Further research should be done to investigate the exact source of contamination.

Over the last few years, Phethalic Acid Esters (PAEs) have attracted a widespread attention due to their widespread production and use. These compounds are not only linked to endocrine disruption and cancer but also considered as emerging and hazardous pollutants. Large amounts of PAEs have been detected in industrial wastewaters. Given the widespread use of biological processes in industrial wastewater treatment, this study aimed to identify biodegradation pathways of PAEs and their potential metabolites. Two short-chain esters from phthalic acid esters including diethyl phthalate (DEP) and diallyl phthalate (DAP) were selected in the present study. We used the survey of metabolites in a moving bed biofilm reactor effluent to determine biodegradation pathways of designated esters at hydraulic retention times of 1 to 12 hours. Influent concentration of 100 mg/l was also considered throughout the study. Phthalic acid, mono-methyl phthalate, dimethyl phthalate and catechol were identified as the most noteworthy metabolites in biodegradation of both esters. The degradation pathway of both studied compounds was similar and involves either detachment of ester-chain or removal of methyl group, followed by few decomposition steps resulting in the production of benzene ring. The degradation can proceed further with ring cleavage and it ends with 2-hydroxy muconic semi-aldehyde. The main route for removal of studied compounds was de-esterification followed by demethylation. According to identifies degradation pathways and metabolites produced, biodegradation can be considered as a reliable treatment process for industrial wastewaters containing PAEs.

Atmospheric dust, also known as a part of PM10, can cause some adverse effects on public health. The aim of this study was to investigate dust concentration trends in Kermanshah city and also to compare related Air Quality Index (AQI) in different years, seasons and months during 2005 to 2012. In this descriptive-analytical study, totally 2589 samples were taken from air monitoring stations owned by the Environmental Protection Agency. The ghatered data were then analyzed using SPSS software V.16. The frequency percentage of PM10 concentrations based on AQI descriptions (healthy, moderate, unhealthy for sensitive groups, unhealthy, very unhealthy and dangerous) were 12.16, 68.36, 12.82, 3.43, 0.77 and 2.43 percents, respectively. It is further interesting to note that in all monitored days during the present study, 19.43% of total days were in unhealthy conditions within AQI> 100. So that, although the frequency of dusty days decreased from summer to fall, failure to meet air quality standard requirements increased from fall to winter and further to spring. The results of this study showed that the observed changes in PM10 concentration were significant in the course of seasons and months. The worst air quality condition occured in summer (specially July). It seems possible that these results are due to frequent dust enterance originating from neighboring countries, humidity reduction, drought and unsustainable use of water resources, temperature rising, as well as wind speed and direction. Because of adverse health effects of particulate matter, it is necessary to promote environmentally aware and responsible science of its trend, short-term and long-term and also international planning to reduce its detrimental impacts.

Soil contamination by copper (Cu) very often occurs in the soil surface layer of vineyard cultivations, due to the heavy use of copper fungicides in order to protect against fungal grape diseases. The objective of this study was therefore to evaluate copper concentration in the superficial layer of vineyard cultivation in Malayer, Iran, and also to prepare the pollution map of copper in this region. Twenty five surface soil samples (0-20 cm) of Malayer vineyard region were collected and consequently were subjected to Cu concentration assessment. Soil samples were air dried and sieved, and the categorized <0.149 mm fraction was used in subsequent digestion operation. The concentrations of Cu in extracted solutions were determined by Flame Atomic Absorption Spectrophotometry. The inverse distance weighting (IDW) method was used to interpolate copper concentrations in the whole study area owing to the limited amount of data. The low concentrations of copper in the range of 3.95 to 15.09 mg/kg with a mean value of 7.36 mg/kg were noticed in the studied vineyard soils. The total Cu concentrations were generally similar to those reported for natural soils. Observed low concentrations of copper in studied vineyard cultivations and indeed homogeneous distribution of copper in the soil, implies that the copper concentrations were controlled by geological processes. Heterogeneous distribution of Cu in the small part of southern region could be linked with anthropogenic impacts.

Cresol is an extremely toxic phenolic compound even at low concentrations whichcan be found in industrial effluents. The aim of this study was, therefore, to assess the ability of modified Azolla and Lemna minor in p-cresol removal from aqueous solution. In the present empirical-bench scale study, we activated the Azolla and Lemna minor by 0.1M HCl and dried in the oven at 105 °C for 24 h. The effects of contact time, pH, initial cresol concentration and biomass amount on adsorption performance were investigated. Adsorption isotherms and kenitics were then used to explain the gathered experimental data. The concentration of p-cresol was measured by UV-VIS spectrophotometer at 280 nm. The results indicated that although the efficiency of p-cresol removal increased by increasing both contact time and the amount of bioadsorbent, the adsorption capacities [qe], however, decreased either in the case of Azolla or Lemna minor. The adsorption capacity also decreased by increasing initial p-cresol concentration. The optimum pH of p-cresol removal was 3. The adsorption process followed the Langmuir isotherm and pseudo-second-order kinetic. According to our results, Azolla and Lemna minor can be used as effective and affordable adsorbents for the removal of phenolic compounds from industrial effluents.

WHO suggests for consumption of fish twice a week. However, studies and reports show that fish consumption in some countries is less than its minimum amount. In the present study, barriers and influencing factors as well as related scientific evidence against fish consumption have been examined. This paper reviews the recent published papers in English and Farsi concerning fish consumption. Using keywords including “fish consumption”, “influencing factors on fish consumption”, “facilitators and barriers to fish consumption”, 20 relevant articles by search engines and databases such as Google Scholar, Pubmed, ScienceDirect, and SID were identified and extracted. Extracted data were then summarized in predesigned tables and consequently qualitative and simple quantitative data analyses were conducted. The review of these studies resulted in 12 obstacles to fish consumption. Unpleasant taste, expensive price, and lack of knowledge were the most important from the viewpoint of the frequency of reported barriers. Furthermore, gender, age, nutritional culture and habits were the most commonly reported factors affecting fish consumption. Before any planning it is vital to identify the most important factors influencing the consumption of fish and the most prominent barriers to consumption in the population studied. Considering the observed statistically significant correlation between demographic characteristics and fish consumption, various promotional programs for people with demographic differences should be applied.

Biosorption is a relatively new clean up method used for the removal of heavy metals from the environment. Entry of heavy metals into the environment may result in change in population structure and further alteration of resistance mechanism(s) in exposed microorganisms. The first question in this study sought to determine the threshold of bacterial resistance to cadmium (Cd). The second question was to identify indigenous bacterial species capable of removing the Cd from the soil and consequently to achieve a more efficient biological treatment for industrial effluents. Natural topsoil samples were obtained from three industrial parks in Hamadan, Iran. The concentration of Cd in soil samples was measured and thence the bacterial cultures were prepared.Following the screening process, the minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] were determined in order to find the threshold of bacterial tolerance. Indeed, the adsorption capacity of bacterial strains came down in favor of the identification of resistant bacteria. Respectively, 42, 4 and 4 bacterial strains were identified for cultures having average cadmium concentrations of 0.78, 500 and 750 mg/L. This experiment did also detect that Tcd2 and Tcd4 showed the highest MIC with 1250 mg Cd/L. Moreover, TCd2, belonging to the family of Enterobacteriaceae and Enterobacter genus, demonstrated the maximum cadmium removal efficiency (30.2%). The test was successful as it was able to identify the indigenous cadmium tolerant bacteria with high adsorption capacity. This finding has important implications for developing special biological wastewater treatment such as a biofilter in the cadmium-releasing industries.